Conventionally, there is a MFP (Multi-Function Peripheral) capable of executing image forming on a sheet using a non-decolorable toner and a decolorable toner. Printing using the non-decolorable toner consumes more power than does printing using the decolorable toner. Therefore, if the printing by the non-decolorable toner is executed often, it is difficult to reduce power consumption by the MFP, or in or at a location where the MFP is present.